Navigation system, apparatus and method for generating navigation message

ABSTRACT

An apparatus for generating a navigation message includes a route generating unit configured to generate a route, and a navigation message generating unit configured to generate a navigation message about the generated route based on the generated route, one or more map information items of the generated route, and an order of priority in which map information items are presented.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority under 35 U.S.C. § 119 toJapanese Patent Application No. 2018-198447 filed on Oct. 22, 2018, theentire content of which is incorporated herein by reference in itsentity.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present disclosure relates to a navigation system, an apparatus anda method for generating a navigation message.

2. Description of the Related Art

In getting to a destination, a visually impaired person may walk indoorsor not with the aid of a sighted person or a guide dog. In some cases, anavigation system or the like may be used through a cellular phone or asmartphone. For example, Japanese Laid-open Patent Publication No.2001-128149 (Patent document 1) discloses a system for voice guidance inwhich a terminal carried by the visually impaired person iscommunicatively connected to a device used by a guide person.

SUMMARY OF THE INVENTION

Embodiments of the present disclosure provide an apparatus, a system anda method so as to provide guidance properly.

A first aspect of an embodiment provides the following apparatus:

An apparatus for generating a navigation message for a person travelingon foot, including:

a route generating unit configured to generate a route, the routeincluding:

nodes from a starting point to a destination, the nodes indicating thestarting point, the destination, and at least one turning pointstherebetween,

one or more map information items, each of which is associated with anobject existing along a path connecting the nodes, and is classified asat least one of an alert item indicating that the object presents dangerto the person, a walking-assistance item indicating that the objectserves to assist walking, and a landmark item indicating that the objectis perceivable by the person; and

a navigation message generating unit configured to generate a navigationmessage about the generated route based on the generated route, the oneor more map information items of the generated route, and an order ofpriority in which map information items are presented,

wherein the navigation message generating unit is configured to include,in the navigation message, a description about a section of thegenerated route, such that,

when an end node at an end of the section is located within apredetermined distance from a given object existing along the section,the description includes a map information item associated with thegiven object as an indication of the end node,

when the given section has one or more map information items classifiedas the alert item or the walking-assistance item, the descriptionincludes the one or more map information items classified as the alertitem or the walking-assistance item, and

when the given section has no map information items classified as eitherthe alert item or the walking-assistance item, and has one or more mapinformation items classified as the landmark item, the descriptionincludes a map information item selected, from the one or more mapinformation items classified as the landmark item, in the order ofpriority in which map information items are presented.

A second aspect of the embodiment provides the following system:

A navigation system, including:

a navigation message generating apparatus for generating a navigationmessage for a person traveling on foot, including:

a route generating unit configured to generate a route, the routeincluding:

-   -   nodes from a starting point to a destination, the nodes        indicating the starting point, the destination, and one or more        turning points therebetween,    -   one or more map information items, each of which is associated        with an object existing along a path connecting the nodes, and        is classified as at least one of an alert item indicating that        the object presents danger to the person, a walking-assistance        item indicating that the object serves to assist walking, and a        landmark item indicating that the object is perceivable by the        person; and    -   a navigation message generating unit configured to generate a        navigation message about the generated route based on the        generated route, the one or more map information items of the        generated route, and an order of priority in which map        information items are presented,

a navigation message output apparatus for outputting a navigationmessage for a person traveling on foot; including:

-   -   a present location obtaining unit configured to obtain a present        location of a person;    -   a direction obtaining unit configured to obtain a direction of        the person;    -   a notification decision unit configured to obtain the route        generated by the navigation message generating apparatus, and        determine the timing of presenting the navigation message based        on the obtained route, and the obtained present location and        direction;    -   an output unit configured to send a notification to the person,        and output the navigation message generated by the navigation        message generating apparatus, and

wherein the navigation message generating unit is configured to include,in the navigation message, a description about a section of thegenerated route, such that,

when an end node at an end of the section is located within apredetermined distance from a given object existing along the section,the description includes a map information item associated with thegiven object as an indication of the end node,

when the given section has one or more map information items classifiedas the alert item or the walking-assistance item, the descriptionincludes the one or more map information items classified as the alertitem or the walking-assistance item, and

when the given section does not have map information items classified aseither the alert item or the walking-assistance item, and has one ormore map information items classified as the landmark item, thedescription includes map information items selected, from the one ormore map information items classified as the landmark item, in the orderof priority in which map information items are presented.

A third aspect of an embodiment provides the following method:

A method for generating a navigation message for a person traveling onfoot, including:

generating a route, the route including:

nodes from a starting point to a destination, the nodes indicating thestarting point, the destination, and one or more turning pointstherebetween,

one or more map information items, each of which is associated with anobject existing along a path connecting the nodes, and is classified asat least one of an alert item indicating that the object presents dangerto the person, a walking-assistance item indicating that the objectserves to assist walking, and a landmark item indicating that the objectis perceivable by the person; and

generating a navigation message about the generated route based on thegenerated route, the one or more map information items of the generatedroute, and an order of priority in which map information items arepresented,

wherein the generating a navigation message includes generating, in thenavigation message, a description about a section of the generatedroute, such that,

when an end node at an end of the section is located within apredetermined distance from a given object existing along the section,the description includes a map information item associated with thegiven object as an indication of the end node,

when the given section has one or more map information items classifiedas the alert item or the walking-assistance item, the descriptionincludes the one or more map information items classified as the alertitem or the walking-assistance item, and

when the given section does not have map information items classified aseither the alert item or the walking-assistance item, and has one ormore map information items classified as the landmark item, thedescription includes map information items selected, from the one ormore map information items classified as the landmark item, in the orderof priority in which map information items are presented.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a functionalconfiguration of a navigation apparatus according to a first embodimentof the present invention;

FIG. 2 is a diagram illustrating an example of a presentation messagegenerated by the navigation apparatus;

FIG. 3 is a flowchart (part 1) illustrating an example of a processoperated by the navigation apparatus;

FIG. 4 is a diagram illustrating an example of path information;

FIG. 5 is a diagram illustrating an example of map information items;

FIG. 6 is a diagram illustrating an example of a route generated by aroute generating unit;

FIG. 7 is a flowchart (part 2) illustrating an example of a processoperated by the navigation apparatus;

FIG. 8 is a flowchart illustrating an example of generating a summary;

FIGS. 9A and 9B are diagrams for explaining an example of a generatedsummary;

FIG. 10 is a flowchart illustrating an example of a process ofgenerating a navigation message according to the first embodiment;

FIGS. 11A and 11B are diagrams for explaining an example of generating anavigation message with respect to a section between a node 1 and a node2;

FIGS. 12A and 12B are diagrams for explaining an example of generating anavigation message with respect to a section between the node 2 and anode 3;

FIGS. 13A and 13B are diagrams for explaining an example of generating anavigation message with respect to a section between the node 3 and anode 4;

FIG. 14 is a diagram illustrating an example of an order of priority inwhich map information items are presented;

FIG. 15 is a flowchart illustrating an example of a process ofgenerating a surrounding-information description;

FIGS. 16A and 16B are diagrams for explaining an example of generating asurrounding-information description with respect to the section betweenthe node 1 and the node 2;

FIG. 17 is a flowchart illustrating an example of a process of updatinga navigation message according to the first embodiment;

FIGS. 18A and 18B are diagrams for explaining an example of updating anavigation message with respect to the section between the node 1 andthe node 2 (in a case where a present location is 120 meters ahead fromthe node 1);

FIG. 19 is a flowchart illustrating an example of a process of updatinga surrounding-information description;

FIGS. 20A and 20B are diagrams for explaining an example of an updatedsurrounding-information description with respect to the section betweenthe node 1 and a node 2 (in a case where a present location is 120meters ahead from the node 1);

FIG. 21 is a diagram illustrating an example of a functionalconfiguration of a navigation apparatus according to a second embodimentof the present invention;

FIG. 22 is a flowchart illustrating an example of a process ofgenerating a navigation message according to the second embodiment;

FIGS. 23A to 23D are diagrams for explaining an example of defining aset of consecutive alert items and an alert item set;

FIGS. 24A and 24B are diagrams for explaining a notification point of anavigation message;

FIGS. 25A and 25B are diagrams for explaining an example of generating anavigation message with respect to a section between a node M and a nodeM+1;

FIG. 26 is a flowchart illustrating an example of a process of updatinga navigation message according to the second embodiment; and

FIG. 27 is a diagram illustrating an example of a hardware configurationof the navigation apparatus according to the first and secondembodiments.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Explanation will be hereinafter provided for embodiments with referenceto the drawings. In the embodiments, a navigation apparatus forproviding a visually impaired person with guidance on a route taken ingetting from a starting point to a destination is described. As anexample of a use case, during walking, the following is considered: avisually impaired person does not need to operate a navigation apparatusin his/her pocket or bag, but receives only a notification based onhis/her location information. Voice guidance is provided for thevisually impaired person in a case where the visually impaired personwho has received the notification stops walking to operate thenavigation apparatus, which is taken from the pocket or the bag. Notethat by way of example, the embodiments each provide a case where thenavigation apparatus gives the visually impaired person voice guidance,but the navigation apparatus may give other persons traveling on footvoice guidance. For example, such persons include persons who do noteasily walk compared to healthy working people, including aged persons,children or the like.

First Embodiment

<Functional Configuration of Navigation Apparatus>

FIG. 1 is a diagram illustrating an example of a functionalconfiguration of a navigation apparatus 100 according to a firstembodiment of the present invention. The navigation apparatus 100 is anapparatus that generates a presentation message, including a navigationmessage for a person traveling on foot, sends a notification to avisually impaired person via vibration as needed, and provides voiceguidance in response to receiving an instruction from the visuallyimpaired person.

FIG. 2 is a diagram illustrating an example of a presentation messagegenerated by the navigation apparatus 100. The presentation messagegenerated by the navigation apparatus 100 may include a summary and asurrounding-information description, in addition to a navigationmessage. The summary is a brief statement for presenting a route such asa distance from a starting point to a destination, a direction withrespect to the starting point and the destination, and the number ofturning points between the starting point and the destination. In a casewhere the starting point, the turning point and the destination are eachrepresented by a node, the navigation message is a message forpresenting a distance from a certain node to the next node, mapinformation item(s) existing along a section to the next node, and thelike. The surrounding-information description is an account of mapinformation item(s) existing around a present location. The mapinformation item includes a map-information-item name indicating a nameof an object relating to a slope or a step existing along a pathconnecting the nodes, a type associated with the map-information-itemname (as described in detail below, the above type includes an alertitem indicating that the object presents danger to the person, awalking-assistance item indicating that the object serves to assistwalking, a landmark item indicating that the object is perceivable bythe person with a sense enabled during walking, and the like), and thelike. The navigation message and the surrounding-information descriptionare updated based on a present location of the person.

As illustrated in FIG. 1, the navigation apparatus 100 includesfunctional units that include a screen input unit 101, a routegenerating unit 103, a presentation message generating unit 105, anavigation control unit 107, and an output unit 109. The navigationapparatus 100 also includes storage units that include a pathinformation storage unit 151, a map-information-item storage unit 153, aroute storage unit 155, and a presentation message storage unit 157. Thepresentation message generating unit 105 includes a summary generatingunit 105-1, a navigation message generating unit 105-2 and asurrounding-information-description generating unit 105-3. Thenavigation control unit 107 includes a present location obtaining unit107-1, a direction obtaining unit 107-2 and a notification decision unit107-3. The output unit 109 includes a vibration generating unit 109-1, apresentation message output unit 109-2, a speech synthesis unit 109-3and an audio output unit 109-4.

The screen input unit 101 always stands ready to receive an inputinstruction from a user such as a visually impaired person. Whenreceiving an instruction of a starting point and a destination as wellas starting navigation, the screen input unit 101 generates aninstruction to cause the route generating unit 103 to generate textinformation of names in terms of the starting point and the destination(hereafter, the text information relating to a starting point name isreferred to as a “starting point,” and the text information relating toa destination name is referred to as a “destination”), as well as aroute taken in getting from the starting point to the destination. Thescreen input unit 101 also outputs the generated instruction as anavigation-starting instruction. When receiving an instruction to finishnavigation, the screen input unit 101 generates an instruction to causethe presentation message generating unit 105 to finish generating apresentation message, and outputs the generated instruction as anavigation-finishing instruction. When receiving an instruction to reada presentation message, the screen input unit 101 generates aninstruction to cause the presentation message generating unit 105 tooutput the presentation message via the output unit 109, and outputs thegenerated instruction as a reading instruction.

The route generating unit 103, whose input includes thenavigation-starting instruction from the screen input unit 101, pathinformation from the route information storage unit 151 and mapinformation item(s) from the map-information-item storage unit 153,outputs a route taken in getting from a starting point to a destination,as well as map information item(s) of the route. Specifically, whenreceiving a navigation-starting instruction including a starting pointand a destination from the screen input unit 101, the route generatingunit 103 generates a route taken in getting from the starting point tothe destination with reference to the route information storage unit 151for storing path information as well as the map-information-item storageunit 153 for storing map information items. Also, the route generatingunit 103 stores the route and map information item(s) about the route inthe route storage unit 155. The route may include a route having ashortest traveling-distance, a route having the smallest number ofturning points, or the like. In the present embodiment, the routestorage unit 155 stores nodes existing along the route from the startingpoint to the destination, as well as map information item(s) of theroute. The generated route is also outputted to the presentation messagegenerating unit 105. Note that the map information items are eachassociated with a corresponding map-information-item name, and an orderof priority in which map information items are presented to the user ispreliminarily set.

The presentation message generating unit 105 includes the summarygenerating unit 105-1, the navigation message generating unit 105-2, andthe surrounding-information-description generating unit 105-3. Thepresentation message generating unit 105, whose input includes a routegenerated by the route generating unit 103 as well as map informationitem(s) of the route, outputs a presentation message (text information)including a summary, a navigation message and a surrounding-informationdescription. Also, the presentation message generating unit 105, whoseinput includes the route stored in the route storage unit 155 and mapinformation item(s) of the route, as well as a notification decision, apresent location and a direction that are obtained from the navigationcontrol unit 107, updates a navigation message and asurrounding-information description, and outputs the updated navigationmessage and surrounding-information description. Also, thepresentation-message generating unit 105, whose input includes a readinginstruction from the screen input unit 101, obtains a presentationmessage from the presentation message storage unit 157, and outputs thepresentation message. Further, the presentation message generating unit105, whose input includes a navigation-finishing instruction from thescreen input unit 101, finishes generating the presentation message.Specifically, the presentation message generating unit 105 generates thepresentation message, including the summary, the navigation message andthe surrounding-information-description, based on a route generated bythe route generating unit 103, map information item(s) of the route, anda predefined order of priority in which map information items arepresented. Also, when the navigation control unit 107 determines that anotification is needed to be sent to a user, the presentation messagegenerating unit 105 updates the navigation message and thesurrounding-information description based on a present location and adirection received from the navigation control unit 107.

The summary generating unit 105-1, whose input includes a routegenerated by the route generating unit 103, outputs a summary.Specifically, the summary generating unit 105-1 generates the summary,including a distance from the starting point to the destination, adirection, and the number of turning points, based on the routegenerated by the route generating unit 105-1. The process of generatingthe summary will be described below.

The navigation message generating unit 105-2, whose input includes aroute generated by the route generating unit 103, and map informationitem(s) of the route, outputs a navigation message. Also, the navigationmessage generating unit 105-2, whose input includes a route stored inthe route storage unit 155 and map information item(s) of the route, aswell as a notification decision, a present location and a direction thatare obtained from the navigation control unit 107, updates thenavigation message, and outputs the updated navigation message.Specifically, the navigation message generating unit 105-2 generates thenavigation message, including a distance to the next node and mapinformation item(s) existing along a section to the next node, based onthe route generated by the route generating unit 103, the mapinformation item(s) of the route, and the order of priority in which mapinformation items are presented. As described in detail below, the orderof priority in which map information items are presented ispreliminarily set based on an alert level of object as to whether theobject used in the guidance presents danger to the person, or aperception ability as to whether the object used in the guidance isperceptible through a sense of hearing. In such a manner, the navigationmessage can include appropriate information to the person. Note that,without a limitation of the sense of hearing, the order of priority maybe set in consideration of at least one of the following sense enabledduring walking: a haptic sense, a temperature sense, a pain sense, avibration sense, a vision sense, a smell sense, or vestibular sensation(balance sense). The above order of priority is set for includingappropriate information in a navigation message even in a case wheremessage words are limited. Alternatively, the above order of priority isset for including appropriate information at the beginning of anavigation message even in a case where a navigation message has along-form description. In this description, the appropriate informationincludes information relating to an object that presents danger to theperson, or/and information relating to an object that physically servesto assist walking. As described below, when the navigation control unit107 detects a change in present locations or directions, the navigationmessage generating unit 105-2 obtains a present location and a directionfrom the navigation control unit 107, and updates the navigationmessage. The process of generating and updating the navigation messagewill be described below.

The surrounding-information-description generating unit 105-3, whoseinput includes a route generated by the route generating unit 103, andmap information item(s), outputs a surrounding-information description.Also, the surrounding-information-description generating unit 105-3,whose input includes the route stored in the route storage unit 155, andmap information item(s) of the route, as well as a notificationdecision, a present location and a direction that are obtained from thenavigation control unit 107, updates the surrounding-informationdescription, and outputs the updated surrounding-informationdescription. The surrounding-information-description generating unit105-3 generates the surrounding-information description, including mapinformation item(s) existing around the present location, based on theroute generated by the route generating unit 103, and the mapinformation item(s). When the navigation control unit 107 detects achange in present locations or directions, thesurrounding-information-description generating unit 105-3 obtains apresent location and a direction from the navigation control unit 107,and updates the navigation message. The process of generating andupdating the surrounding-information description will be describedbelow.

The presentation message generating unit 105 stores the generatedpresentation message in the presentation message storage unit 157. Whenreceiving a notification decision from the navigation control unit 107,the presentation message generating unit 105 retrieves a presentationmessage from the presentation message storage unit 157 accordingly, andthen outputs the presentation message to the presentation message outputunit 109-2. Also, when receiving a reading instruction from the screeninput unit 101, the presentation message generating unit 105 retrieves apresentation message from the presentation message storage unit 157accordingly, and outputs the presentation message to the speechsynthesis unit 109-3. Further, when receiving a navigation-finishinginstruction from the screen input unit 101, the presentation messagegenerating unit 105 finishes generating the presentation messageaccordingly.

The navigation control unit 107 includes the present location obtainingunit 107-1, the direction obtaining unit 107-2, and the notificationdecision unit 107-3. The navigation control unit 107, whose inputincludes a navigation-starting instruction and a navigation-finishinginstruction from the screen input unit 101, outputs a present locationand a direction of the visually impaired person, as well as anotification decision for indicating the timing of presenting anavigation message. Upon receiving a navigation-starting instructionfrom the screen input unit 101, the navigation control unit 107periodically outputs a present location and a direction of the visuallyimpaired person to the presentation message generating unit 105 until anavigation-finishing instruction is received. Further, the navigationcontrol unit 107 determines the timing of presenting a navigationmessage based on a route stored in the route storage unit 155, a presentlocation and a direction of the visually impaired person.

The present location obtaining unit 107-1, whose input includes anavigation-starting instruction or a navigation-finishing instructionfrom the screen input unit 101, outputs a present location. The presentlocation obtaining unit 107-1 periodically obtains a present location(e.g., latitude and longitude) of the visually impaired person, andoutputs the present location to the notification decision unit 107-3.The present location obtaining unit 107-1 can obtain a present locationvia a GPS (Global Positioning System), for example. In detecting achange in present locations, the present location obtaining unit 107-1outputs a present location to the presentation message generating unit105 for updating a presentation message. In the present embodiment, asan example, assuming that a traveling distance is updated at 1-meterintervals in a case of walking at 1 meter per second, the “periodically”means 1-second intervals. Also, for example, the “in detecting a changein present locations” means a case where a distance of the differencebetween a most recently obtained location and a present location exceedsa predetermined threshold. In the present embodiment in which atraveling distance is updated at 1-meter intervals, for example, thepredetermined threshold is 1 meter.

The direction obtaining unit 107-2, whose input includes anavigation-starting instruction or a navigation-finishing instructionfrom the screen input unit 101, outputs a direction. The directionobtaining unit 107-2 obtains a direction of the visually impaired person(e.g., orientation with respect to a traveling direction in which thevisually impaired person travels), and outputs the direction to thenotification decision unit 107-3. For example, the direction obtainingunit 107-2 predicts a traveling direction of the visually impairedperson based on the change in present locations, and considers thepredicted traveling direction as the direction of the visually impairedperson. In detecting a change in directions, the direction obtainingunit 107-2 outputs a direction to the presentation message generatingunit 105 for updating a presentation message. For example, the “indetecting a change in directions” means a case where an angle of thedifference between a most recently obtained direction and a presentdirection exceeds a predetermined threshold. For example, assuming thatsuch an angle is represented by a clock position (which is given fromamong the twelve hour positions in which the hands of a clock point),the predetermined threshold is 30 degrees that correspond to a 1-hourangle.

The notification decision unit 107-3, whose input includes a presentlocation from the present location obtaining unit 107-1, a directionfrom the direction obtaining unit 107-2 and a route stored in the routestorage unit 155, outputs a notification decision for indicating thetiming of presenting a navigation message, as well as a vibrationinstruction. The notification decision unit 107-3 compares a presentlocation of the visually impaired person, obtained by the presentlocation obtaining unit 107-1, with a notification point (e.g., alocation of each node, a point that is 10 meters before a given nodeexcept for a starting point) of the route. Also, the notificationdecision unit 107-3 determines if a present location of the visuallyimpaired person is at a given notification point of the route. If thepresent location of the visually impaired person is at the givennotification point of the route, the notification decision unit 107-3determines that a notification is needed to be sent to the visuallyimpaired person. In determining that a notification is needed to be sentto the visually impaired person, the notification decision unit 107-3outputs a notification decision to the presentation message generatingunit 105, and outputs a vibration instruction that is an instruction tocause the vibration generating unit 109-1 to vibrate.

The output unit 109 includes the vibration generating unit 109-1, thepresentation message output unit 109-2, and the speech synthesis unit109-3. The output unit 109, whose input includes a presentation messageoutputted from the presentation message generating unit 105, outputs anotification for outputting a presentation message, as well as apresentation message. In a case where the presentation messagegenerating unit 105 outputs a presentation message to the speechsynthesis unit 109-3 in accordance with a reading instruction, thepresentation message in audio format is outputted via the audio outputunit 109-4.

The vibration generating unit 109-1, whose input includes a vibrationinstruction from the notification decision unit 107-3, generatesvibration. The vibration generating unit 109-1 generates vibration,e.g., with use of a vibration function of a smartphone, in accordancewith a vibration instruction outputted when the notification decisionunit 107-3 determines that a notification is needed to be sent to thevisually impaired person. In such a manner, the visually impaired personcan recognize the timing of receiving a navigation message throughvibration. Thereby, the visually impaired person can input a readinginstruction through the screen input unit 101.

The presentation message output unit 109-2, whose input includes apresentation message from the presentation message generating unit 105,outputs (displays) a presentation message received from the presentationmessage generating unit 105 onto a screen.

The speech synthesis unit 109-3, whose input includes a presentationmessage from the presentation message generating unit 105, generates asynthesized speech signal based on the presentation message receivedfrom the presentation message generating unit 105 in accordance with areading instruction, and outputs the synthesized speech signal.

The audio output 109-4, whose input includes a synthesized speech signalfrom the speech synthesis unit 109-3, outputs the synthesized speech.

<Process of Navigation Apparatus>

Hereafter, the process operated by the navigation apparatus 100 isdescribed.

FIG. 3 is a flowchart illustrating an example of a process operated bythe navigation apparatus 100. The flowchart of FIG. 3 illustrates a casewhere the navigation apparatus 100 performs first processing ingenerating and storing a presentation message in accordance with anavigation-starting instruction.

At step S1, the screen input unit 101 receives names of a starting pointand a destination, and passes, to the route generating unit 103, anavigation-starting instruction that is an instruction for generating aroute taken in getting from the starting point to the destination,including text information indicating the names of the starting pointand the destination (hereafter, the text information of a starting pointname is referred to as a “starting point”, and the text information of adestination name is referred to as a “destination”). Note that as aninput manner, a keyboard, or a sound input (e.g., in a case ofconverting an input voice into text information through voicerecognition) may be used, or alternatively, other input manners may beused.

At step S2, based on the starting point and the destination, the routegenerating unit 103 obtains path information from the path informationstorage unit 151, and obtains map information item(s) from themap-information-item storage unit 153. FIG. 4 illustrates an example ofpath information. FIG. 5 illustrates an example of map informationitems. In an example of FIG. 4, the path information includes a pathname, a starting point, a destination, latitude and longitude withrespect to each of nodes located along a route taken in getting from thestarting point to the destination. In an example of FIG. 5, the mapinformation items each include a map-information-item name, a type ofmap information items, a line or dot, latitude and longitude, right orleft, and orientation. The “type” of map information items is used forclassifying map information items to be presented to the visuallyimpaired person into a plurality of categories. In the presentembodiment, each of the map information items is classified as at leastone of an alert item indicating that the object presents danger to theperson, a walking-assistance item indicating that the object serves toassist walking, and a landmark item indicating that the object isperceivable by the person with a sense enabled during walking. Note thatthe sense enabled during walking includes a sense of hearing, a hapticsense, a temperature sense, a pain sense, a vibration sense, a visionsense, a smell sense, vestibular sensation (balance sense), or the like.The “line or dot” means attribution of object, e.g., indicating a casewhere a given map information item exists at a certain position in asection between the nodes (which corresponds to the “dot”), or where agiven map information item exists continuously in whole or in part in asection between the nodes (which corresponds to the “line”). Brailleblocks or the like is an example of the line attribution. The “latitudeand longitude” indicate location information indicative of a center of aplace where a given map information item exists. The “right or left”means a side on which a given object exists when it is viewed from apredetermined direction. The “orientation” means a particular directionslanting from horizontal. Note that in the present embodiment, the mapinformation items relate to objects located in an indoor area such as astation yard. However, they may relate to objects located in an outdoorarea, such as pedestrian lights, crosswalks, bus stops, articles foremitting a sound, or/and articles for assisting a visually impairedperson who walks, such as Braille blocks. At step S2, the routegenerating unit 103 obtains a path that matches both of the startingpoint and the destination, from the path information storage unit 151,and obtains map information item(s) existing along the path based onlatitude and longitude of the path, from the map-information-itemstorage unit 153.

At step S3, the route generating unit 103 generates a route based on thestarting point, the destination, the path information and the mapinformation item(s). FIG. 6 illustrates an example of a route generatedby the route generating unit 103. In an example of FIG. 6 in which astarting point, turning points and a destination are each represented asa node, the route includes nodes existing from the starting point to thedestination, as well as map information items existing between thenodes. In FIG. 6, with respect to a “distance to the next node,” a “nextturning direction,” a “distance from a prior node,” “right or left” and“orientation,” they are each calculated based on “latitude andlongitude” with respect to a given node(s) or a given map informationitem(s), as well as a traveling direction obtained with use of thelatitude and longitude. With respect to the “distance to the next node”and the “next turning direction”, they are each involved at only a pointof a node. With respect to the “distance from a prior node,” the “rightor left” and the “orientation,” they are each involved at a point of amap information item. In FIG. 6, with respect to each map informationitem, in which the “distance from a prior node” indicates the mark “-,”its attribution with respect to the “line or dot” in FIG. 5 indicatesthe line. This is because the map information item with respect to theline attribution continuously exists in whole or in part of a givensection. In this example of FIG. 5, such a map information item is notinvolved with respect to the “distance to the next node” and the“distance from a prior node.” Note that a “notification point” indicatesa point where a notification is needed to be sent to the visuallyimpaired person. In this example, at all points of nodes, the respectivenotifications are needed to be sent. The generated route is passed tothe presentation message generating unit 105 by the route generatingunit 103. The generated route is stored in the route storage unit 155.

At step S4, the presentation message generating unit 105 generates apresentation message based on the route. Note that in this description,the presentation message refers to a message that includes the summary,the navigation message and the surrounding-information description, asillustrated in FIG. 2. FIG. 8 is a flowchart of generating a summary.FIG. 10 is a flowchart of generating a navigation message. FIG. 15 is aflowchart of generating a surrounding-information description. Thesewill be described below.

At step S5, the presentation message generating unit 105 passes thepresentation message to the presentation message output unit 109-2, andoutputs the presentation message via the presentation message outputunit 109-2. The presentation message is outputted onto a screen of adevice such as a smartphone. The presentation message is stored in thepresentation message storage unit 157. Note that the presentationmessage may be directly outputted onto a screen of a device such as asmartphone. Instead of such a manner, in a case where a buttonindicating “screen reading” is displayed on a touch panel screen, thebutton may be pressed (the button displayed in the touch panel screen istouched) to receive an instruction to read the presentation message.Alternatively, a button for receiving an instruction to read aninstruction message, or the like may be displayed while the presentationmessage is directly outputted. For example, such a button may be set soas to be fully displayed in an area for displaying a presentationmessage at a smartphone. In the above button manner, if the instructionto read a presentation message is received, an operation of thenavigation apparatus 100 is performed as in the case of receiving theinstruction to read a presentation message at the screen input unit 101.

FIG. 7 is a flowchart illustrating an example of a process operated bythe navigation apparatus 100. FIG. 7 illustrates a whole processoperated by the navigation apparatus 100, after step S5 in FIG. 3, inorder to provide voice guidance in accordance with a readinginstruction, which is received after a notification is sent, or updatean indication message based on location information.

At step S6, the presentation message generating unit 105 determines if anavigation-finishing instruction is not received from the screen inputunit 101. For example, it is determined if a navigation-finishing buttondisplayed on a screen is pressed, or if a navigation-finishinginstruction is made using a voice command. If the navigation-finishinginstruction is not received, the process proceeds to step S7, or if thenavigation-finishing instruction is received, the process is finished.

At step S7, the presentation message generating unit 105 determines if areading instruction of a presentation message is not received. Forexample, it is determined if an area for displaying a presentationmessage is not touched at a smartphone. If the reading instruction isreceived, the process proceeds to step S8, or if the reading instructionis not received, the process proceeds to step S11.

At step S8, the presentation message generating unit 105 obtains, fromthe presentation message storage unit 157, a presentation message basedon the reading instruction, and passes the presentation message to thespeech synthesis unit 109-3.

At step S9, the speech synthesis unit 109-3 generates a synthesizedspeech signal based on the presentation message received from thepresentation message generating unit 105, and passes the synthesizedspeech signal to the audio output unit 109-4. Note that as a speechsynthesis system constituting the speech synthesis unit 109-3, anysynthesis system may be used.

At step S10, the audio output unit 109-4 outputs a synthesized speechinto which the synthesized speech signal received from the speechsynthesis unit 109-3 is converted. For example, the synthesized speechis outputted from a speaker, an earphone or a headphone of a smartphone.The process then proceeds to step S11.

At step S11, the present location obtaining unit 107-1 of the navigationcontrol unit 107 periodically obtains a present location to output thepresent location to the notification decision unit 107-3. The directionobtaining unit 107-2 periodically obtains a direction to output thedirection to the notification decision unit 107-3.

At step S12, the navigation control unit 107 determines if either of thepresent location or the direction, or both of them have changed. If bothhave not changed, the process returns to step S6, or if either haschanged, the process proceeds to step S13.

At step S13, the navigation control unit 107 passes the changed presentlocation or direction to the presentation message generating unit 105,and updates the presentation message. The navigation message and thesurrounding-information description are the subject to update, asillustrated in FIG. 2. FIG. 17 is a flowchart of updating a presentationmessage. FIG. 19 is a flowchart of updating a surrounding-informationdescription. These will be described below.

At step S14, the presentation message generating unit 105 passes theupdated presentation message to the presentation message output unit109-2 to output the presentation message via the presentation messageoutput unit 109-2. The presentation message is stored in thepresentation message storage unit 157.

At step S15, the notification decision unit 107-3 determines if anotification is needed to be sent to a user. Whether a notification isneeded to be sent is determined based on latitude and longitude of agiven node(s) existing along the route. As a point where a notificationis needed to be sent, a location of each node, as well as points thatare each 10 meters before a given node except for the starting point areused. Note that, with respect to the points that are each 10 metersbefore a given node, a distance to a given node may be changed asneeded. In a case of comparing the present location with such a pointwhere a notification is needed to be sent, if it is determined that anotification is needed to be sent (e.g., in a case where the userreaches a given node, and/or where the user reaches 10 meters before agiven node except for the starting point), the process proceeds to stepS16. If it is determined that the notification is not needed, theprocess returns to step S6.

At step S16, the notification decision unit 107-3 of the navigationcontrol unit 107 sends a vibration instruction to the vibrationgenerating unit 109-1, and then the vibration generating unit 109-1generates vibration. For example, such vibration is implemented by avibration function of a smartphone. Note that, aside from the visuallyimpaired person, the notification may be sent to children with use of asound signal. Alternatively, the notification may be sent to thevisually impaired person with use of a light signal. For example, thevibration may stop after a lapse of a predetermined period. Thevibration may stop by an operation by the visually impaired person via ascreen. The vibration may stop when it is detected that the visuallyimpaired person stops walking. After the vibration is generated, theprocess returns to step S6. The process at a subsequent step S6continues until a navigation-finishing instruction is received.

Note that, in FIG. 7, a flowchart in a sequence that the navigationapparatus 100 follows is illustrated. However, a part of the process inFIG. 7 is concurrently operated. For example, the process of steps S11to S16 and the process of steps S7 to S10 are concurrently operated.

<Generation of Summary>

Hereafter, the process of generating a summary by the summary generatingunit 105-1 at step S4 in FIG. 3 is described. FIG. 8 is a flowchartillustrating an example of a process of generating a summary.

First, at step 4-1-1, the summary generating unit 105-1 obtains a wholeroute taken in getting from the starting point to the destination. As anexample, FIG. 5 illustrates the obtained whole route.

Next, at step S4-1-2, the summary generating unit 105-1 calculates adirection of the destination, a traveling distance to the destination,and the number of turning points based on the obtained route. In theexample of the route in FIG. 5, the route corresponds to a route asillustrated in FIG. 9A. In the example of the route in FIG. 9, an anglewith respect to a starting point (e.g., node 1) and a destination (e.g.,node 4) is calculated, and further, a direction of the destination isdetermined by matching the calculated angle with a clock position havinga closest value that is selected from among the twelve clock positions.A traveling distance to the destination is calculated by adding eachdistance between the adjacent two nodes that are selected from among thenodes 1 to 4. The number of turning points is calculated by adding thenumber of nodes excluding the starting point and the destination.

At step S4-1-3, the summary generating unit 105-1 generates a summarybased on the direction of the destination, the traveling distance to thedestination, and the number of turning points. For example, with respectto the route in FIG. 5, as illustrated in FIG. 9B, the message “thedestination is at a traveling distance of 440 meters from the startingposition in a 1 o'clock direction. On the way, make two turns” isgenerated.

<Generation of Navigation Message>

Hereafter, the process of generating the navigation message by thenavigation message generating unit 105-2 at step S4 in FIG. 3 isdescribed. FIG. 10 is a flowchart illustrating an example of the processof generating the navigation message according to the first embodiment.

First, at step S4-2-1, the navigation message generating unit 105-2divides the route into N−1 sections based on N nodes, e.g., a sectionbetween nodes 1 and 2, a section between nodes 2 and 3, . . . , asection between nodes M and M+1, . . . , a section between nodes N−1 andN (M<N, M is an integer of 1 or more, and N is an integer of 2 or more).In this description, one section refers to a section from one node toanother node adjacent thereto, where another node exists next after theone node in the traveling direction.

At step S4-2-2, a parameter M indicating a section where a navigationmessage is generated is set to 1.

At step S4-2-3, the navigation message generating unit 105-2 obtains asection between the node M and the node M+1. For example, in the case ofM=1, a section between the node 1 and the node 2 is obtained based onthe route of FIG. 6, as illustrated in FIG. 11A. Note that, at asubsequent step S4-2-16, M is incremented. In the case of M=2, a sectionbetween the node 2 and the node 3 is obtained as illustrated in FIG.12A. In the case of M=3, a section between the node 3 and the node 4 isobtained as illustrated in FIG. 13A. Note that in the presentembodiment, assuming that a navigation message is generated at eachturning point, explanation will be provided for a case where eachsection between the nodes located along the route is obtained, by way ofexample. However, the number of obtained sections is not limited to one,and multiple sections may be obtained.

At step S4-2-4, with reference to a distance from a prior node, thenavigation message generating unit 105-2 determines if there is no mapinformation item within a distance of 5 meters to the next node. Ifthere is a map information item within a distance of 5 meters to thenext node, the process proceeds to step S4-2-5, and then the navigationmessage generating unit 105-2 obtains one map information item that isthe closest to the next node. If there is no map information item withina distance of 5 meters to the next node, the process proceeds to stepS4-2-6. Note that, as a distance to the next node, around 5 meters arepreferably used, but any value may be used as long as it is smaller thana distance (in the above example, 10 meters) between a given node and anotification point that is before the given node. The number of obtainedmap information items is not limited to one, and multiple mapinformation items may be obtained. In a case of obtaining multiple mapinformation items, the navigation message may be generated so as topresent a relationship between the multiple map information items, suchas a distance between an elevator and stairs. In FIG. 11A, because thereis no map information item within a distance of 5 meters to the node 2,the process proceeds to step S4-2-6. In the example of FIG. 12A, becausea distance from “escalator” to the next node is 2 meters, the processproceeds to step S4-2-5, and then the navigation message generating unit105-2 obtains the map information item about the “escalator”.

At step S4-2-6, with reference to a column of the type with respect to agiven route, the navigation message generating unit 105-2 determines ifthere is no alert item or walking-assistance item with respect to eachmap information item. In the example of FIG. 11A, because “stairs” and a“pillar” each indicate the alert item, it is determined that alert itemsare present.

At step S4-2-6, if an alert item or a walking-assistance item ispresent, the process proceeds to step S4-2-7, and then the navigationmessage generating unit 105-2 obtains all of the alert item(s) and thewalking-assistance item(s). In the example of FIG. 11A, the “step” andthe “pillar” are obtained. At step S4-2-7, in a case of obtaining all ofthe alert item(s) and the walking-assistance item(s), the processproceeds to step S4-2-10.

At step S4-2-6, if there are no alert items and walking-assistanceitems, the process proceeds to step S4-2-8, and then the navigationmessage generating unit 105-2 determines if there is a landmark item. Ifthere is no landmark item, the process proceeds to step S4-2-10,otherwise the process proceeds to step S4-2-9. In the example of FIG.13A, because a “wall” and an “elevator” each indicate the type oflandmark, the process proceeds to step S4-2-9.

At step S4-2-9, the navigation message generating unit 105-2 obtains onelandmark item according to an order of priority in which map informationitems are presented. Note that the number of obtained landmark items isnot limited to one, and multiple landmark items may be obtained. FIG. 14illustrates an example of the order of priority in which map informationitems are presented. The mark “-” with respect to the order of priorityindicates a map information item classified as an alert item or awalking-assistance item. Since such a map information item is includedin a navigation message, the order of priority is not set. For thisreason, with respect to each map information items classified as thelandmark item, the order of priority is set. In a case where there aremultiple landmark items located along a given route, a landmark itemhaving a smallest number with respect to the order of priority, i.e., alandmark item having a highest order of priority, is selected from amongthe multiple landmark items. In the example of FIG. 14, in a case ofselecting one landmark item from among two landmark items about a “wall”and an “elevator,” existing along a section of the route, the “wall” hasan eighth-order of priority, and the “elevator” has a sixth-order ofpriority. In this example, because the “elevator” takes priority overthe “wall,” the landmark item about the “elevator” is obtained. Notethat in the present embodiment, the type of map information item (thealert item, the walking-assistance item, or the landmark item), or theorder of priority in which map information items are presented may beset in consideration of a result of questionnaires for the visuallyimpaired person. Alternatively, a dangerous object that may be stumbledon or be bumped during walking may indicate the alert item. An objectproviding information about a path or an object serving to assistwalking may indicate the walking-assistance item. Other objects each mayindicate the landmark item. The order of priority in which mapinformation items are presented may be set according to a perceptionability from hearing with respect to the object used in the guidance.With respect to a landmark item for emitting a sound that lets theperson know a presence of the landmark item (e.g., in the case of an“escalator,” the announcement “this is an up escalator” is made andincludes an operating noise), it may have a high order of priority.Also, the classification of map information items or the order ofpriority in which landmark items are presented may be preliminarily setor changed in consideration of a user such as the visually impairedperson.

At step S4-2-10, the navigation message generating unit 105-2 generatesa message based on the route. In this description, the message in whicha turning direction is placed after a traveling distance is generated.For example, the message “at a distance of 200 meters, turn right” isgenerated. Note that, the forward distance and the turn direction arenot required to be arranged in a consecutive manner; the navigationmessage generating unit 105-2 may add word(s) between the travelingdistance and the turning direction.

At step S4-2-11, the navigation message generating unit 105-2 determineswhether to obtain a map information item within a distance of 5 metersto the next node. If such a map information item is obtained, theprocess proceeds to step S4-2-12, otherwise the process proceeds to stepS4-2-13.

At step S4-2-12, the navigation message generating unit 105-2 generatesa message in which the map information item within a distance of 5meters to the next node is presented as an indication to find a turningpoint. For example, the message “a down escalator is an indication of aturning point” is generated.

At step S4-2-13, the navigation message generating unit 105-2 determineswhether to obtain an alert item, a walking-assistant item or/and alandmark item. If such an item is obtained, the process proceeds to stepS4-2-14, otherwise the process proceeds to step S4-2-15.

At step S4-2-14, the navigation message generating unit 105-2 generatesa message based on the alert item, the walking-assistant item or/and thelandmark item. For example, when obtaining alert item(s) orwalking-assistant item(s), the navigation message generating unit 105-2generates the message based on all of the obtained alert item(s) andwalking-assistant item(s). Also, when obtaining one landmark item basedon the order of priority, the navigation message generating unit 105-2generates the message based on the obtained landmark item. As anexample, the navigation message generating unit 105-2 generates themessage in which location information of the map information item isplaced after a corresponding map-information-item name. For example, themessage “an automatic door is 50 meters ahead on the right” isgenerated. Note that, there being no limitation to such a form toarrange the map-information-item name and the location informationconsecutively, the navigation message generating unit 105-2 may addword(s) between the two.

At step S4-2-15, it is determined if M is equal to N−1, i.e., ifnavigation messages with respect to all sections are generated. If thereis a section where a navigation message is not generated, the processproceeds to step S4-2-16. If navigation messages with respect to allsections are generated, the process is finished.

At step S4-2-16, a value of the parameter M is increased by one (whichmay be referred to as an increment hereafter), and then the processreturns to step S4-2-3.

In the above flowchart, as an example, explanation has been provided forthe case where, after obtaining all of the alert item(s) and thewalking-assistance item(s) at step S4-2-7, the process proceeds to stepS4-2-10. However, the process may proceed to step S4-2-8. In this case,given that, at step S4-2-8, a navigation message is generated based onthe alert item(s), the walking-assistance item(s) and the landmarkinformation, the navigation message may have a long-form description. Inorder to reduce a user's burden to listen to such a navigation message,if the alert item(s) and the walking-assistance item(s) are obtained,the navigation message is preferably generated based on the alertitem(s) and the walking-assistance item(s) so as to have an appropriateamount of the navigation message.

FIGS. 11B, 12B and 13B illustrate examples of a generated message. Ineach figure, location information of a map information item is placedafter a map-information-item name. Thereby, the map information item iseasily recognized by the visually impaired person that wants to checkthe map information item and that considers it important. For example,given that the visually impaired person wants to check information aboutstairs only, if a map-information-item name is presented after locationinformation of a map information item through voice guidance, thevisually impaired person needs to check if the “stairs” are presentedafter the memorized location information of the map information item. Onthe other hand, in a case where a map-information-item name is presentedfirst, the visually impaired person can memorize the locationinformation presented after the “stairs” is announced, thereby easilyrecognizing necessary information. Also, in the present embodiment, aturning direction is placed after a traveling distance, thereby easilyrecognizing a whole route.

According to other rules of generating a navigation message, withrespect to a map information item whose attribution with respect to the“line/dot” indicates the line, although location information of the mapinformation item is not presented after a map-information-item name,only information about right or left or/and orientation is presented.For example, since the attribution with respect to the Braille blocks inFIG. 12A indicates the “line,” such a map information item is notinvolved with respect to the “distance from a prior node”. In such amanner, for example, the message “on the way, Braille blocks are on theleft” as illustrated in FIG. 12B is generated, without includingdistance information.

Also, in a case where there are a plurality of map information itemshaving a same map-information-item name and existing along a sectionbetween the nodes, e.g., in a case where the “stairs going down” arerespectively 20 meters ahead, 30 meters ahead, and 40 meters ahead in asection from a certain node to the next node, the message is generatedsuch that the number of map information items is placed after locationinformation of the map information item that is followed by themap-information-item name. As an example, the message “on the way,stairs going down at 20 meters, 30 meters, and 40 meters ahead: 3 stairsgoing down in total” is generated. Note that, there is no limitation tosuch a form of arranging the map information item, the locationinformation and the map information item name consecutively in themessage; the navigation message generating unit 105-2 may add word(s)between the map-information-item name and the location information, aswell as between the location information and the number of mapinformation items.

In this description, assuming that a description of the message ispresented at each turning point (node), the message presents mapinformation item(s) existing along a section from a certain turningpoint to the next turning point. However, if a distance from a certainnode to the next node is shorter than a distance between a notificationpoint and a turning point, map information item(s) existing along asection from a certain node to the node after the next may be presented.For example, in a case where the notification point is 10 meters beforea given turning point, and a distance between a node N and a node N+1 is5 meters, a description of the message is generated so as to present twotopics at the beginning of the description, along with presenting mapinformation item(s) existing along the section from the node to the nodeafter the next. As an example, the message “guidance on two topics: at adistance of 10 meters, turn right. On the way, at a distance of 3meters, stairs going down are on the right. Next, at a distance of 5meters, turn left. On the way, Braille blocks are on the left” isgenerated.

<Generation of Surrounding-Information Description>

Hereafter, the process of generating the surrounding-informationdescription by the surrounding-information-description generating unit105-3 at step S4 in FIG. 3 is described. FIG. 15 is a flowchartillustrating an example of generating the surrounding-informationdescription.

First, at step S4-3-1, the surrounding-information-descriptiongenerating unit 105-3 separates the route into N−1 sections based on Nnodes, e.g., a section between nodes 1 and 2, a section between nodes 2and 3, . . . , a section between nodes M and M+1, . . . , a sectionbetween nodes N−1 and N (M<N, M is an integer of 1 or more, and N is aninteger of 2 or more). In this description, one section refers to asection from one node to another node adjacent thereto, where anothernode exists next after the one node in the traveling direction.

At step S4-3-2, the parameter M indicating a section where asurrounding-information description is generated is set to 1.

At step S4-3-3, the surrounding-information-description generating unit105-3 obtains a section between the node M to the node M+1. For example,in the case of M=1, a section between the node 1 and the node 2 isobtained based on the route of FIG. 6, as illustrated in FIG. 16A. Notethat at a subsequent step S4-3-7, the parameter M is incremented, sothat other sections are obtained. Note that in the present embodiment,explanation will be provided for a case where a surrounding-informationdescription is generated based on map information item(s) existing alonga section between the nodes, by way of example. However, map informationitem(s) existing within a predetermined distance of a present locationmay be obtained for generating a surrounding-information description.

At step S4-3-4, the surrounding-information-description generating unit105-3 obtains all of the alert item(s), the walking-assistance item(s)and the landmark item(s) existing in the section obtained by thesurrounding-information-description generating unit 105-3. In an exampleof FIG. 16A, all items about “stairs”, a “pillar” and an “automaticdoor” are obtained.

At step S4-3-5, the surrounding-information-description generating unit105-3 generates a description in which location information of a mapinformation item is placed after a map-information-item name. Forexample, the message “an automatic door is 50 meters ahead on the right”is generated. In such a manner, the map information items are placed inan order in which map information items are close from the front in thetraveling direction. FIG. 16B illustrates an example of a generateddescription.

At step S4-3-6, it is determined if M is equal to N−1, i.e., ifsurrounding-information descriptions with respect to all sections aregenerated. If there is a section where a surrounding-informationdescription is not generated, the process proceeds to step S4-3-7. Ifsurrounding-information descriptions with respect to all sections aregenerated, the process is finished.

At step S4-3-7, the parameter M is incremented, and then process returnsto step S4-3-3.

<Update of Navigation Message>

Hereafter, the process of generating the navigation message by thenavigation message generating unit 105-2 at step S13 in FIG. 7 isdescribed. FIG. 17 is a flowchart illustrating an example of a processof updating the navigation message according to the first embodiment.

First, at step S13-1-1, the navigation message generating unit 105-2obtains a section between the node M existing immediately prior to apresent location and the next node M+1 based on a given route. Forexample, in a case where the present location is between a node 1 and anode 2, as illustrated in FIG. 18A, a section between the node 1 and thenode 2 is obtained based on the route of FIG. 6.

At step S13-1-2, with reference to a distance from a prior node, thenavigation message generating unit 105-2 determines if there is no mapinformation item within a distance of 5 meters to the next node. Ifthere is a map information item within a distance of 5 meters to thenext node, the process proceeds to step S13-1-3, and then the navigationmessage generating unit 105-2 obtains one map information item that isthe closest to the next node. If there is no map information item withina distance of 5 meters to the next node, the process proceeds to stepS13-1-4. Note that, as a distance to the next node, any threshold valuemay be used, except for 5 meters. The number of obtained map informationitems is not limited to one, and multiple map information items may beobtained. In the example of FIG. 18A, since there is no map informationitem within a distance of 5 meters to the next node, the processproceeds to step S13-1-4.

At step S13-1-4, with reference to a column of the type with respect toa given route, the navigation message generating unit 105-2 determinesif there is no alert item or walking-assistance item with respect toeach map information item. In the example of FIG. 18A, assuming that apresent location is 120 meters ahead from the node 1, it is found thatthe present location is between the “pillar” and the “automatic door”with reference to a distance from the prior node. In such a manner, atthis step, it is determined if there is no alert item orwalking-assistance item with respect to map information item(s) existingafter the “automatic door.” In the example of FIG. 18A, because the“automatic door” indicates a landmark item, it is determined that thereis no alert item or walking-assistance item.

At step S13-1-4, if there is an alert item or a walking-assistance item,the process proceeds to step S13-1-5, and then the navigation messagegenerating unit 105-2 obtains all of the alert item(s) and thewalking-assistance item(s). The process then proceeds to step S13-1-8.

At step S13-1-4, if there are no alert items and walking-assistanceitems, the process proceeds to step S13-1-6. At step S13-1-6, withrespect to map information item(s) of the route taken from the presentlocation, the navigation message generating unit 105-2 determines ifthere is a landmark item. If there is no landmark item, the processproceeds to step S13-1-8, otherwise the process proceeds to stepS13-1-7. In the example of FIG. 18A, because there is the “automaticdoor” existing after the present location, the navigation messagegenerating unit 105-2 determines if there is a landmark item, and thenthe process proceeds to step S13-1-7.

At step S13-1-7, the navigation message generating unit 105-2 obtainsone landmark item in the order of priority in which map informationitems are presented. In the example of FIG. 18A, because only the“automatic door” existing after the present location indicates thelandmark item, the landmark information about the “automatic door” isobtained.

At step S13-1-8, the navigation message generating unit 105-2recalculates distances and orientation based on the present location anddirection information. In the example of FIG. 18A, because the presentlocation is 120 meters ahead from the node 1, a distance from thepresent location to the “automatic door” is obtained as 10 m=130 m-120m. Also, a distance from the present location to the node 2 is obtainedas 30 m=150 m-120 m.

At step S13-1-9, the navigation message generating unit 105-2 generatesa message based on a given route. As an example, the navigation messagegenerating unit 105-2 generates the message in which a turning directionis placed after a traveling distance. For example, the message “at adistance of 200 meters, turn right” is generated.

At step S13-1-10, the navigation message generating unit 105-2determines whether to obtain a map information item within a distance of5 meters to the next node. If such a map information item is obtained,the process proceeds to step S13-1-11, otherwise the process proceeds tostep S13-1-12.

At step S13-1-11, the navigation message generating unit 105-2 generatesa message in which the map information item within a distance of 5meters to the next node is presented as an indication to find a turningpoint. For example, the message “a down escalator is an indication of aturning point” is generated.

At step S13-1-12, the navigation message generating unit 105-2determines whether to obtain an alert item, a walking-assistance itemor/and a landmark item. If such an item is obtained, the processproceeds to step S13-1-13, otherwise the process is finished.

At step S13-1-13, the navigation message generating unit 105-2 generatesa message based on the alert item, the walking-assistance item or/andthe landmark item. For example, when obtaining the alert item or thewalking-assistance item, the navigation message generating unit 105-2generates a message based on all of the obtained alert item(s) andwalking-assistance item(s). Also, when obtaining one landmark item inthe order of priority in which map information items are presented, thenavigation message generating unit 105-2 generates a message based onthe obtained landmark item. As an example, the navigation messagegenerating unit 105-2 generates the message in which locationinformation of a map information item is placed after amap-information-item name. For example, the message “an automatic dooris 50 meters ahead on the right” is generated.

<Update of Surrounding-Information Description>

Hereafter, the process of generating the surrounding-informationdescription by the surrounding-information-description generating unit105-3 at step S13 in FIG. 7 is described. FIG. 19 is a flowchartillustrating an example of a process of updating thesurrounding-information description.

At step S13-2-1, the surrounding-information-description generating unit105-3 obtains a section between the node M existing immediately prior toa present location and the next node M+1, based on a given route. Forexample, in a case where the present location is between the node 1 andthe node 2, as illustrated in FIG. 20A, a section between the node 1 andthe node 2 is obtained based on the route of FIG. 6.

At step S13-2-2, the surrounding-information-description generating unit105-3 obtains all of alert item(s), walking-assistance item(s) andlandmark item with respect to map information item(s) existing in theobtained section. In an example of FIG. 20A, all items about “stairs”, a“pillar” and an “automatic door” are obtained. In generating asurrounding-information description, all map information items existingalong a section between the node 1 and the node 2 are the subject,unlike the case of generating the navigation message.

At step S13-2-2, the surrounding-information-description generating unit105-3 recalculates distances and orientation based on a present locationand direction information. In the example of FIG. 20A, because thepresent location is 120 meters ahead from the node 1, a distance fromthe present location to the “stairs” is obtained as −100 m=20 m-120 m (aminus in front of a number indicates a backward position). A distance tothe “pillar” is obtained as −20 m=100 m-120 m. A distance to the“automatic door” is obtained as 10 m=130 m-120 m.

At step S13-2-4, the surrounding-information-description generating unit105-3 generates a description in which location information of a mapinformation item is placed after a map-information-item name. Forexample, the message “an automatic door is 50 meters ahead on the right”is generated. In this case, map information item(s) existing after thepresent location in the traveling direction are sequenced in an order ofproximity of the map information items to the present location. Further,following such map information item(s), the remaining map informationitem(s) sequenced in an order of proximity of the map information itemsto the present location backward in the traveling direction. FIG. 20Billustrates an example of a generated description.

Second Embodiment

As an example, in the first embodiment, explanation has been providedfor the case where all alert items existing along a given sectionbetween the nodes are presented in one navigation message. However, in acase where multiple alert items exist along the section between thenodes, if all of the alert items are presented in one navigationmessage, a user such as a visually impaired person may not easilymemorize those alert items. In view of the above, preferably, thosealert items presented may be divided into many separated descriptions,or alternatively, they may be summarized so as to give a briefdescription. In a second embodiment, in light of a user's burden oflistening, as an example, explanation will be provided below for a casewhere the number of alert items presented in one navigation message isset based on location information of each alert item and the number ofalert items.

<Functional Configuration of Navigation Apparatus>

FIG. 21 is a diagram illustrating an example of a functionalconfiguration of a navigation apparatus 100 according to the secondembodiment.

In the second embodiment, the navigation apparatus 100 has a similarfunction to that in FIG. 1. However, the navigation message generatingunit 105-2 has a different function from that in the first embodiment,since alert items presented are divided into many separate descriptions.In such a manner, the respective notifications with respect to theseparate descriptions are sent. In view of the above, unlike the firstembodiment, the respective notification points of the navigationmessages are inputted into a notification decision unit 107-3 from apresentation message storage unit 157. Further, a notification decisionunit 107-3 has a different function from that in the first embodiment.

A navigation message generating unit 105-2, whose input includes a routegenerated by a route generating unit 103, and map information item(s) ofthe route, outputs a navigation message. Also, the navigation messagegenerating unit 105-2, whose input includes a route stored in a routestorage unit 155 and map information item(s) as well as a notificationdecision, a present location and a direction that are obtained from thenavigation control unit 107, updates a navigation message to output theupdated navigation message. For example, in a case where a plurality ofalert items exist along a section to the next node, the navigationmessage generating unit 105-2 defines a set of alert items, from amongthe existing alert items, based on a distance between points where thealert items exist, as well as the number of alert items. In such amanner, the navigation message generating unit 105-2 generates anavigation message for each set of alert items. Also, in updating anavigation message as well, in a case where a plurality of alert itemsexist along a section to the next node, the navigation messagegenerating unit 105-2 defines a set of alert items, from among theexisting alert items, based on a distance between the points where thealert items exist, as well as the number of alert items, and generates anavigation message with respect to each set for updating. Further, thenavigation message generating unit 105-2 sets a notification point wherea navigation message generated with respect to each set of alert itemsis presented (e.g., the notification point is 5 meters before a point ofa first placed alert item with respect to each set of alert itemsfollowing a first set of alert items). Note that, in a case where analert item exists at a notification point (e.g., 10 meters before a nodeexcluding the starting point) set before a given node, the navigationmessage generating unit 105-2 may release a setting of such anotification point so as to cancel the notification (the notification isnot performed). The process of generating and updating the navigationmessage will be described below.

The notification decision unit 107-3, whose input includes a presentlocation from a present location obtaining unit 107-1, a direction froma direction obtaining unit 107-2, a route stored in the route storageunit 155 and a notification point of a navigation message stored in thepresentation message storage unit 157, outputs a notification decisionfor indicating the timing of presenting a navigation message, as well asa vibration instruction. The notification decision unit 107-3 comparesvalues with respect to the present location of the visually impairedperson obtained by the present location obtaining unit 107-1, a givennotification point of the route, a notification point set by thenavigation message generating unit 105-2 and the setting of releasing anotification point, and then determines if the present location of thevisually impaired person is at the notification point. If it isdetermined that the present location of the visually impaired person isat the notification point, the notification decision unit 107-3determines that the notification is needed to be sent to the visuallyimpaired person.

<Generation of Navigation Message>

Hereafter, the process of generating a navigation message by thenavigation message generating unit 105-2 according to the secondembodiment is described below.

FIG. 22 is a flowchart illustrating an example of the process ofgenerating a navigation message according to the second embodiment. Theprocess illustrated in FIG. 22 is operated after step S4-2-7 in FIG. 10.

At step S4-4-1, the navigation message generating unit 105-2 determinesif there are two or more alert items among the item(s) obtained at stepS4-2-7. If there are two or more alert items, the process proceeds tostep S4-4-2. If there is one or no alert item, the process proceeds tostep S4-4-10.

At step S4-4-2, the navigation message generating unit 105-2 determinesif each distance between the points of two alert items selected fromamong the alert items is less than 10 meters. In a case where eachdistance between the points of the two alert items is less than 10meters, and further, the two alert items are adjacent, the processproceeds to step S4-4-3. If such a distance is 10 meters or more evenwith respect to one pair of alert items, the process proceeds to stepS4-4-4. Note that in the present embodiment, as a criteria fordetermining if a distance between the points of two alert items isshort, 10 meters are used by way of example. However, other distancesmay be used as the criteria, as long as the distance between the pointsof two alert items is within a distance between adjacent nodes of agiven route, and the two alert items are considered as existingconsecutively by the user.

At step S4-4-3, the navigation message generating unit 105-2 defines aset of consecutive alert items that consists of all alert items (in thefollowing description, a set of alert items in which a distance betweenadjacent two alert items is within a distance of less than 10 meters maybe referred to as a “set of consecutive alert items”). In an example ofFIG. 23A, with respect to a section between a node M and a node M+1, ina case where each distance between the points of adjacent two alertitems selected from among three alert items is less than 10 meters, aset of consecutive three alert items is defined. In such a manner, adistance between a first alert item and the last alert item may be 10meters or more, as illustrated in FIG. 23A. At step S4-4-3, in the caseof defining a set of consecutive alert items, the process proceeds tostep S4-4-10.

At step S4-4-4, the navigation message generating unit 105-2 determinesif the number of alert items is two. If the number of alert items istwo, the process proceeds to step S4-4-10 because a distance between thepoints of the two alert items is 10 meters or more. In the case of threealert items, the process proceeds to step S4-4-5.

At step S4-4-5, the navigation message generating unit 105-2 determinesif a distance between two adjacent alert items, which are selected fromamong the two or more alert items, is less than 10 meters. If such adistance is less than 10 meters, the process proceeds to step S4-4-6. Ifsuch a distance is 10 meters or more, the process proceeds to stepS4-4-7.

At step S4-4-6, the navigation message generating unit 105-2 defines aset of consecutive alert items that consists of the adjacent two alertitems in which a distance between their alert items is less than 10meters as determined at step S4-4-5. In an example of FIG. 23B, withrespect to a section between a node M and a node M+1, a distance betweenthe points of a second alert item and a third alert item is 10 meters ormore. On the other hand, a distance between the points of a first alertitem and a second alert item is less than 10 meters. Further, a distancebetween the points of a third alert item and a fourth alert item is lessthan 10 meters. In such a manner, a set of consecutive alert items thatconsists of first and second alert items, as well as a set ofconsecutive alert items that consists of third and fourth alert items,are defined. At step S4-4-6, in a case of defining a set of consecutivealert items that consists of adjacent two alert items in which adistance therebetween is less than 10 meters, the process proceeds tostep S4-4-7.

At step S4-4-7, the navigation message generating unit 105-2 determinesif alert items whose number is an odd number of three or more and thatexist in order from a node M are not defined as a set. In other words,it is determined if the number of alert items existing in order from thenode M, which are not defined as a set of consecutive alert itemsconsisting of adjacent two alert items, is three or more. If such alertitems are not defined as a set, the process proceeds to step S4-4-8,otherwise the process proceeds to step S4-4-9.

At step S4-4-8, the navigation message generating unit 105-2 defines, asan alert item set, a single alert item that is the closest to the nodeM, selected from among the alert items whose number is an odd number ofthree or more and existing in order from the node M. For example, asillustrated in FIG. 23C, in a case where three alert items existing inorder from the node M are not defined as a set, a single alert item thatis the closest to the node M is defined as an alert item set. In thecase of defining such a set, the process proceeds to step S4-4-9.

At step S4-4-9, the navigation message generating unit 105-2 defines analert item set that consists of adjacent two alert items existing inorder from the traveling direction, selected from among alert items thatare not defined as a set. In other words, the navigation messagegenerating unit 105-2 defines an alert item set that consists ofadjacent two alert items existing in order from the node N+1, selectedfrom among alert items that are not defined as a set and that existalong in a section between the node M and the node M+1. For example, inan example of FIG. 23D, a second alert item and a third alert itemexisting in order from the node M are not defined as a set. In thisexample, an alert item set that consists of adjacent two alert itemsexisting in order from the traveling direction, e.g., a direction fromthe node M+1 to the node M, is defined. In a case of defining an alertitem set that consists of adjacent two alert items selected from amongthree or more alert items, if a total number of selected alert items isan even number such as 6, two alert items from among all alert items aredefined as a set. In contrast, if a total number of alert items is anodd number such as 3, there are two options to define an alert item set.One is to define an alert item set that consists of adjacent two alertitems, selected from alert items excluding a first alert item, to bedefined as a set. Another is to define an alert item set that consistsof adjacent two alert items, selected from alert items excluding thelast alert item, to be defined as a set. In the present embodiment, in acase of defining an alert item set that consists of two alert itemsselected from among odd-numbered alert items, at step S4-4-8, a singlealert item that is the closest to the node M is defined as an alert itemset, thereby shortening a message to be presented at a point where thenode M exists. At the point of the node M, a traveling distance, aturning direction, map information item(s) existing along a section tothe next node, and the like are presented. In such a manner, in order todecrease the number of alert items to be presented at the point of thenode M, in a case where alert items whose number is an odd number of 3or more and that are not defined as a set exist, the number of alertitems to be presented at the point of the node M is one. Note that inthe present embodiment, explanation has been provided for the case ofdefining an alert item set that consists of adjacent two alert items onaccount of a user's burden of listening. However, three or more alertitems may be defined as a set. In other words, in a case where L (L isan integer of 2 or more) alert items existing in order from the node Mare not defined as a set, given that P (P is an integer of 2 or more)alert items are defined as a set, the number of alert items to bepresented at the point of the node M indicates remainder Q (Q is aninteger of 1 or more) obtained in a division of L divided by P. Also, inorder to reduce a user's burden of listening at once, each of alertitems that are not defined as a set may be defined as a set (in thiscase, step S4-4-2 to step S4-4-9 are skipped). Alternatively, given thatthe number of alert items to be presented at the point of the node M isone, an alert item set consisting of L alert items as well as an alertitem set consisting of Q alert items may be defined for presenting. In acase of defining an alert item set consisting of adjacent two alertitems or an alert item set (which may be referred to as a set of alertitems) consisting of one alert item that is not defined as a set, theprocess proceeds to step S4-4-10.

At step S4-4-10, the navigation message generating unit 105-2 determinesif a notification point that is 10 meters before a given node is same asa point where an alert item exists, or is within a distance covered by aset of consecutive alert items or an alert item set. In other words, thenavigation message generating unit 105-2 determines if the point of thealert item is at the notification point, or is within a predetermineddistance (e.g., a distance from a first alert item to the last alertitem existing in the traveling direction along the route) of thesection, in which alert items at both ends of the set of consecutivealert items or the alert item set are located. Note that, assuming thateach point that is 10 meters before a corresponding node, excluding thestarting point, is set as a notification point at step S4-4-10, if thenotification point is at the point or in the section as described above,the process proceeds to step S4-4-11, otherwise the process proceeds tostep S4-4-12.

At step S4-4-11, the navigation message generating unit 105-2 releases asetting of a given notification at a notification point (that is 10meters before a given node) of the notification (so as not to send anotification). In an example of FIG. 24A, a certain point of an alertitem is at the notification point that is 10 meters before the node M+1.In such a manner, the setting of the notification to be sent at thepoint that is 10 meters before the node M+1 is released (in FIG. 24A,the “notification is off” is indicated). In this example, if such anotification is sent, the user may stop walking near such a point of thealert item, and thus this may be negatively affected. For this reason,the above notification is not sent as described above. In a case ofreleasing the setting of the notification at a given notification point,the process proceeds to step S4-4-12.

At step S4-4-12, the navigation message generating unit 105-2 newlysets, as a notification point, a point that is 5 meters before a firstalert item existing in each set of alert items (including a set ofconsecutive alert items and an alert item set), excluding a first set ofalert items that is the closest to the node M. In an example of FIG.24B, three alert items are divided into two sets. In this example, thenavigation message generating unit 105-2 newly sets, as a notificationpoint, a point that is 5 meters before a first alert item existing in asecond set of alert items (in FIG. 24B, the “notification is on” isindicated). The presentation message storage unit 157 stores the settingof releasing a notification point as well as the new notification point,along with the navigation message. In the present embodiment, as thenotification point, the point that is 5 meters before a given alert itemis set, in consideration of a shortened traveling distance in a sectionin which alert items exist, as well as a case where the user is not ableto stop walking after a notification is sent, or where there is alocation error. However, as the newly set notification point, otherpoints may be set, as long as they are points that are each before thenotification point determined at S4-4-10 or step S4-4-11.

At step S4-2-10 in FIG. 10, the navigation message generating unit 105-2generates a message based on the route, as described in the firstembodiment.

At step S4-2-14 in FIG. 10, the navigation message generating unit 105-2generates a message based on the alert item(s), the walking-assistanceitem(s) or/and the landmark item. With respect to the set of alertitems, the navigation message generating unit 105-2 generates anavigation message with respect to each set. In the example of FIG. 23A,the navigation message generating unit 105-2 generates, as a navigationmessage with respect to the node M, a navigation message based on threealert items. In the example of FIG. 23B, the navigation messagegenerating unit 105-2 generates, as a navigation message with respect tothe node M, a navigation message based on the first alert item and thesecond alert item. Further, the navigation message generating unit 105-2generates, as a navigation message to be presented at a point that isbefore the third alert item, a navigation message based on the thirdalert item and the fourth alert item. In the example of FIG. 23D, thenavigation message generating unit 105-2 generates, as a navigationmessage with respect to the node M, a navigation message based on thefirst alert item. Further, the navigation message generating unit 105-2generates, as a navigation message to be presented at a point that isbefore the second alert item, a navigation message based on the secondalert item and the third alert item.

At step S15 in FIG. 7, the notification decision unit 107-3 obtains thesetting of releasing a notification point and the notification pointstored in the presentation message storage unit 107-3, and determines ifa notification is needed to be sent to the user. Note that, in a casewhere the navigation message generating unit 105-2 sets a newnotification point, the output unit 109 outputs the navigation messagegenerated before such a new notification point is set, until the userreaches the new notification point. After the user passes the newnotification point, the output unit 109 outputs the navigation messagegenerated after the new notification point is set.

FIG. 25B illustrates an example of a generated navigation message. Forthe example of FIG. 25A, a message with respect to a section from a nodeM to a node M+1 is divided into two separate parts. In this example,with respect to each part, the message as generated is illustrated inFIG. 25B. With respect to a section from the node M to a point that is 5meters before stairs going down, the message with respect to the node Mis outputted. With respect to a section from the point that is 5 metersbefore stairs going up, the message with respect to the section from thestairs going up is outputted. In this example, the message is generatedfor each part. However, if all alert items are presented at once, theuser may not easily listen to them. For this reason, the message isgenerated for each part, as described above. Also, when generating amessage with respect to a set of consecutive alert items, the navigationmessage generating unit 105-2 generates a message in which locationinformation with respect to each of the alert items following a firstalert item is omitted, and the word “followed by” is used. The message“on the way, stairs going down followed by stairs going up areconsecutively 10 meters ahead” is of an example of the generatedmessage. Thereby, the consecutively placed stairs can be easilyperceived. In FIG. 25B, location information of a map information itemis placed after a map-information-item name. In this example, themap-information-item name and the location information of the mapinformation item are placed in this order, thereby enabling easilylistening to necessary information, without suffering from an excess ofstress in the guidance.

<Update of Navigation Message>

Hereafter, the process of updating a navigation message by thenavigation message generating unit 105-2 according to the secondembodiment is described.

FIG. 26 illustrates an example of updating a navigation messageaccording to the second embodiment. The process illustrated in FIG. 26is operated after step S13-1-5 in FIG. 17.

At step S13-3-1, the navigation-message generating unit 105-2 determinesif there are two or more alert items among the item(s) obtained at stepS13-1-5. If there are two or more alert items, the process proceeds tostep S13-3-2. If there is one or no alert item, the process proceeds tostep S13-1-10.

At step S13-3-2, the navigation message generating unit 105-2 determinesif each distance between the points of two alert items, selected fromamong the alert items, is less than 10 meters. In a case where eachdistance between the points of the two alert items is less than 10meters, and further, the two alert items are adjacent, the processproceeds to step S13-3-3. Even if such a distance is 10 meters or morewith respect to one pair of alert items, the process proceeds to stepS13-3-4.

At step S13-3-3, the navigation message generating unit 105-2 defines aset of consecutive alert items that consists of all alert items. In sucha manner, the process proceeds to step 13-3-10.

At step S13-3-4, the navigation-message generating unit 105-2 determinesif the number of alert items is two. If the number of alert items istwo, the process proceeds to step S13-3-10, because a distance betweenthe points of the two alert items is 10 meters or more. In the case ofthree alert items, the process proceeds to step S13-3-5.

At step S13-3-5, the navigation message generating unit 105-2 determinesif a distance between two adjacent alert items, which are selected fromamong the two or more alert items, is less than 10 meters. If such adistance is less than 10 meters, the process proceeds to step S13-3-6.If such a distance is 10 meters or more, the process proceeds to stepS13-3-7.

At step S13-3-6, the navigation message generating unit 105-2 defines aset of consecutive alert items that consists of the adjacent two alertitems, selected from among the alert items in which a distance betweenadjacent two alert items is less than 10 meters, as determined at stepS13-3-5.

At step S13-3-7, the navigation message generating unit 105-2 determinesif alert items whose number is an odd number of three or more and whichexist in order from a node M are not defined as a set of consecutivealert items. If such alert items are not defined as a set of consecutivealert items, the process proceeds to step S13-3-8, otherwise the processproceeds to step S13-3-9.

At step S13-3-8, the navigation message generating unit 105-2 defines,as an alert item set, a single alert item that is the closest to thenode M, selected from among the alert items whose number is an oddnumber of three or more and existing in order from the node M. If such asingle alert item is defined as an alert item set, the process proceedsto step S13-3-9.

At step S13-3-9, the navigation message generating unit 105-2 defines analert item set that consists of adjacent two alert items existing inorder from the traveling direction, selected from among alert items thatare not defined as a set. The process then proceeds to step S13-3-10.

At step S13-3-10, the navigation message generating unit 105-2determines if a notification point that is 10 meters before a given nodeis same as a point where the given alert item exists, or is within adistance covered by a set of consecutive alert items or an alert itemset. If such a notification point is same as the point or in the sectionas described above, the process proceeds to step S13-3-11, otherwise theprocess proceeds to step S13-3-12.

At step S13-3-11, the navigation message generating unit 105-2 releasesa setting of a given notification (at a point that is 10 meters before agiven node) of the notification.

At step S13-3-12, the navigation message generating unit 105-2 newlysets, as a notification point, a point that is 5 meters before a firstalert item existing in each set of alert items (including a set ofconsecutive alert items and an alert item set), excluding a first set ofalert items that is the closest to the node M. The presentation messagestorage unit 157 stores the setting of releasing a notification point aswell as the new notification point, along with the navigation message.

At step S13-1-8 in FIG. 17, the navigation message generating unit 105-2recalculates distances and orientation based on the present location anddirection information, as described in the first embodiment.

At step S13-1-13 in FIG. 17, the navigation message generating unit105-2 generates a message based on the alert item(s), thewalking-assistance item(s) or the landmark item. In a case of defining aset of alert items, the navigation message generating unit 105-2generates the message with respect to each set.

<Hardware Configuration of Navigation Apparatus>

FIG. 27 is a diagram illustrating an example of a hardware configurationof the navigation apparatus 100 according to the first and secondembodiments. The navigation apparatus 100 may be a computer thatincludes a processor such as a CPU (Central Processing Unit) 191, amemory device 192 such as a RAM (Random Access Memory) or a ROM (ReadOnly Memory), and a storage device 193 such as a hard disk. For example,a program and data stored in the storage device 193 or the memory device192 are executed by the CPU 191 to implement a function and a process ofthe navigation apparatus 100. An input and output interface device 194may enable data to be inputted into the navigation apparatus 100 orenable data to be outputted from the navigation apparatus 100. Note thatthe input and output interface device 194 may be physically separatedfrom the navigation apparatus 100. For example, the navigation apparatus100 may be a smartphone having a touch screen (which is implemented byone hardware component including a liquid crystal display with a touchsensor), a tablet, a notebook PC (personal computer), a desktop PC, orthe like.

Note that, with respect to functional units for generating a navigationmessage in the navigation apparatus 100, such as the route generatingunit 103 and the presentation message generating unit 105, they may beimplemented by a single navigation message generating apparatus. Also,in a case where a client and a server perform the processing describedabove, the client may include the screen input unit 101, the navigationcontrol unit 107 and the output unit 109, which serve as a navigationmessage output apparatus. Also, the server may include the routegenerating unit 103, the presentation message generating unit 105, andthe like, which serve a navigation message generating apparatus. Withrespect to processing units excluding the screen input unit 101, thenavigation control unit 107 and the output unit 109, their functions anddata may be implemented using a distributed system for communicating viathe Internet or the like.

<Supplement of Embodiments>

According to the embodiments, the navigation apparatus 100 canappropriately send a notification in providing voice guidance, therebyproviding a visually impaired person with voice guidance as requested bythe visually impaired person. In such a manner, it is possible to assistthe visually impaired person in order to reach the destination safely,without suffering from an excess of stress in the guidance. Inconsideration of sound leakage, the visually impaired person canperceive the message to reach the destination.

Also, the presentation message is generated with respect to each sectionfrom one turning point to another turning point, thereby presentingappropriate contents and amount of information. It is possible to assistthe visually impaired person without suffering from an excess of stressin the guidance.

The presentation message is generated based on location information ofthe visually impaired person, thereby providing voice guidance accordingto a present location of visually impaired person.

In a case where many alert items are located between the nodes, amessage about their items is presented so as to be divided into separateparts, thereby presenting a short message, without suffering from anexcess of stress in the guidance.

For the sake of convenience of description, in the embodiments, theconfiguration of the navigation apparatus 100 has been described withreference to the functional block diagrams. However, such a navigationapparatus 100 may be implemented by hardware, software, or a combinationthereof. For example, in the embodiments, a program is executed by acomputer to implement the function of the navigation apparatus 100. Aprogram or the like is executed by a computer to implement the processof the method available to the navigation apparatus 100. Also, withrespect to the functional units of the navigation apparatus 100, two ormore among them may be combined as needed. In the embodiments, the steporder described above may be changed.

This disclosure has been described for the case where the word order orthe like is changed, without suffering from an excess of stress in theguidance. The disclosure is not limited to the embodiments. Variousmodifications or changes to the embodiments may be made within the scopeof claims of the present invention.

What is claimed is:
 1. An apparatus for generating a navigation messagefor a person traveling on foot, comprising: a route generating unitconfigured to generate a route, the route including: nodes from astarting point to a destination, the nodes indicating the startingpoint, the destination, and at least one turning points therebetween,one or more map information items, each of which is associated with anobject existing along a path connecting the nodes, and is classified asat least one of an alert item indicating that the object presents dangerto the person, a walking-assistance item indicating that the objectserves to assist walking, and a landmark item indicating that the objectis perceivable by the person; and a navigation message generating unitconfigured to generate a navigation message about the generated routebased on the generated route, the one or more map information items ofthe generated route, and an order of priority in which map informationitems are presented, wherein the navigation message generating unit isconfigured to include, in the navigation message, a description about asection of the generated route, such that, when an end node at an end ofthe section is located within a predetermined distance from a givenobject existing along the section, the description includes a mapinformation item associated with the given object as an indication ofthe end node, when the given section has one or more map informationitems classified as the alert item or the walking-assistance item, thedescription includes the one or more map information items classified asthe alert item or the walking-assistance item, and when the givensection has no map information items classified as either the alert itemor the walking-assistance item, and has one or more map informationitems classified as the landmark item, the description includes a mapinformation item selected, from the one or more map information itemsclassified as the landmark item, in the order of priority in which mapinformation items are presented.
 2. The apparatus according to claim 1,wherein the order of priority in which map information items arepresented is set according to a perception ability from hearing withrespect to the object used in the navigation.
 3. The apparatus accordingto claim 1, wherein the map information item includes amap-information-item name indicating a name of the object located alongthe path connecting the nodes, and includes location informationindicating a location of the object, and wherein the navigation messagegenerating unit is configured to generate the navigation message, suchthat in the description, the location information of the map informationitem is placed after a corresponding map-information-item name.
 4. Theapparatus according to claim 1, wherein the map information itemincludes an attribution of object as to whether the object located alongthe path connecting the nodes is continuously formed in whole or in partin the section, and includes location information indicating a locationof the object, and wherein the navigation message generating unit isconfigured to generate the navigation message, such that, when theattribution of object indicates that the object located along the pathconnecting the nodes is continuously formed in whole or in part in thesection, the description does not include the location information of acorresponding map information item.
 5. The apparatus according to claim1, wherein the map information item includes a map-information-item nameindicating a name of the object located along the path connecting thenodes, and includes location information indicating a location of theobject, and wherein the navigation message generating unit is configuredto generate the navigation message, such that, when the given sectionhas multiple map information items that have a same map-information-itemname, the same map-information-item name, the location information ofeach map information item, and the number of the map information itemsare sequenced in this order.
 6. The apparatus according to claim 1,wherein the navigation message generating unit is configured to generatethe navigation message, such that, when the given section has multiplemap information items that are classified as the alert items and arelocated within a predetermined distance, the multiple map informationitems are defined as a set, and with respect to each set of mapinformation items, the description does not include location informationof each of second and subsequent map information items.
 7. The apparatusaccording to claim 6, wherein the navigation message generating unit isconfigured to generate the navigation message, such that, when the givensection does not have a set of L (L is an integer of two or more) mapinformation items that are classified as the alert items and that arelocated from a starting node of the section, and a remainder Q obtainedin a division of L divided by a predetermined number P (P is an integerof two or more) is one or more, the description includes Q mapinformation items with respect to the starting node, and includes one ormore sets of adjacent P map information items at a notification point ofthe navigation message, the notification point being set with respect toeach set of adjacent P map information items.
 8. The apparatus accordingto claim 6, wherein the navigation message generating unit is configuredto generate the navigation message, such that, with respect to astarting node of the section, the description includes a map informationitem that is classified as the alert item and that is closest to thestarting node, and includes a set of adjacent map information items,whose number is a predetermined number, at a notification point of thenavigation message, the notification point being set with respect toeach set of adjacent map information items.
 9. A navigation system,comprising; a navigation message generating apparatus for generating anavigation message for a person traveling on foot, comprising: a routegenerating unit configured to generate a route, the route including:nodes from a starting point to a destination, the nodes indicating thestarting point, the destination, and one or more turning pointstherebetween, one or more map information items, each of which isassociated with an object existing along a path connecting the nodes,and is classified as at least one of an alert item indicating that theobject presents danger to the person, a walking-assistance itemindicating that the object serves to assist walking, and a landmark itemindicating that the object is perceivable by the person; and anavigation message generating unit configured to generate a navigationmessage about the generated route based on the generated route, the oneor more map information items of the generated route, and an order ofpriority in which map information items are presented, a navigationmessage output apparatus for outputting a navigation message for aperson traveling on foot; comprising: a present location obtaining unitconfigured to obtain a present location of a person; a directionobtaining unit configured to obtain a direction of the person; anotification decision unit configured to obtain the route generated bythe navigation message generating apparatus, and determine the timing ofpresenting the navigation message based on the obtained route, and theobtained present location and direction; an output unit configured tosend a notification to the person, and output the navigation messagegenerated by the navigation message generating apparatus, and whereinthe navigation message generating unit is configured to include, in thenavigation message, a description about a section of the generatedroute, such that, when an end node at an end of the section is locatedwithin a predetermined distance from a given object existing along thesection, the description includes a map information item associated withthe given object as an indication of the end node, when the givensection has one or more map information items classified as the alertitem or the walking-assistance item, the description includes the one ormore map information items classified as the alert item or thewalking-assistance item, and when the given section does not have mapinformation items classified as either the alert item or thewalking-assistance item, and has one or more map information itemsclassified as the landmark item, the description includes mapinformation items selected, from the one or more map information itemsclassified as the landmark item, in the order of priority in which mapinformation items are presented.
 10. A method for generating anavigation message for a person traveling on foot, comprising:generating a route, the route including: nodes from a starting point toa destination, the nodes indicating the starting point, the destination,and one or more turning points therebetween, one or more map informationitems, each of which is associated with an object existing along a pathconnecting the nodes, and is classified as at least one of an alert itemindicating that the object presents danger to the person, awalking-assistance item indicating that the object serves to assistwalking, and a landmark item indicating that the object is perceivableby the person; and generating a navigation message about the generatedroute based on the generated route, the one or more map informationitems of the generated route, and an order of priority in which mapinformation items are presented, wherein the generating a navigationmessage includes generating, in the navigation message, a descriptionabout a section of the generated route, such that, when an end node atan end of the section is located within a predetermined distance from agiven object existing along the section, the description includes a mapinformation item associated with the given object as an indication ofthe end node, when the given section has one or more map informationitems classified as the alert item or the walking-assistance item, thedescription includes the one or more map information items classified asthe alert item or the walking-assistance item, and when the givensection does not have map information items classified as either thealert item or the walking-assistance item, and has one or more mapinformation items classified as the landmark item, the descriptionincludes map information items selected, from the one or more mapinformation items classified as the landmark item, in the order ofpriority in which map information items are presented.